This invention relates to the fuel system of an internal combustion engine, and more particularly to a vapor separator for use in an engine fuel system.
In a fuel injected engine, it is common to employ a vapor separator to separate light vapors from the fuel before injecting the fuel into the engine. This prevents the vapors from being included with the injected fuel, which otherwise would result in the engine running at a leaner than optimum air-fuel ratio. A vapor separator typically entails an enclosed reservoir in which a predetermined level of fuel is maintained, with the fuel vapors being vented from the upper portion of the reservoir. Fuel is discharged from the vapor separator through an opening formed in a bottom wall of the reservoir, and is supplied to a high-pressure fuel pump for pumping the fuel to the fuel injectors. In addition, in a marine application of an internal combustion engine, it is common to employ a water separating filter upstream of the vapor separator for eliminating water from the fuel. A low-pressure pump, operating from pressure generated within the engine crankcase, supplies fuel from the fuel tank to the water separating filter, whereafter the fuel flows to the vapor separator and to the high-pressure pump.
In the past, the above-mentioned components have been separately mounted to the engine in various locations and removed from each other. This entails connecting hoses between the outlet of the low-pressure pump and the inlet of the water separating filter, as well as between the water separating filter outlet and the vapor separator inlet; the vapor separator outlet and the high pressure pump inlet; and the high pressure pump outlet and the fuel injectors. Accordingly, many separate parts must be produced, and each assembled to the engine and the hose connections made between the parts.
The present invention has as its object to provide a compact package for the various elements disposed between the low pressure pump and the fuel injectors. Yet another object of the invention is to reduce the number of parts which must be assembled to the engine, and accordingly the number of steps involved in assembling the parts to the engine.
In accordance with the invention, a vapor separator for the fuel system of an internal combustion engine comprises an enclosed fuel reservoir, formed of a bowl member and a cover member for enclosing the open top of the bowl member. A reservoir inlet is interconnected with the engine fuel system for providing fuel to the reservoir. A fuel pump is disposed within the reservoir, and has an inlet located toward the lower portion of the reservoir for supplying fuel to the fuel pump from the reservoir. The fuel pump has an outlet for discharging fuel therefrom to the fuel injectors. The cover member preferably includes an opening through which the upper end of the fuel pump projects, and sealing structure is provided for enclosing the reservoir about the fuel pump. A vent is provided in the cover member for venting vapors from the fuel contained within the bowl member. The inlet to the reservoir is preferably provided in the cover member. A mounting plate is provided within the reservoir for supporting and mounting the lower end of the fuel pump within the reservoir. The outer edge of the mounting plate engages a lip formed on an inner wall of the bowl member, to provide support for the lower end of the fuel pump. With the inlet of the fuel pump being located in the interior of the bowl member, the hose connection between the fuel pump and the vapor separator is eliminated. In addition, a compact arrangement is provided for mounting the fuel pump to the engine through the vapor separator.
The invention further contemplates a method of constructing a vapor separator, substantially in accordance with the foregoing summary.
In accordance with another aspect of the invention, a water separating filter mounting portion is provided on the cover member, and is adapted to receive a water separating filter such that the filter is located exteriorly of the walls of the bowl member. The mounting portion includes an inlet for supplying fuel to the inlet of the filter, and an outlet for receiving fuel from the filter outlet. A passage is formed in the cover member, extending between and communicating with the mounting portion outlet and the reservoir inlet, for supplying fuel to the reservoir from the mounting portion outlet. With this arrangement, the hose connection between the outlet of the water separating filter and the inlet of the vapor separator is eliminated, and a compact arrangement is provided for mounting of the water separating filter to the engine through the vapor separator.
The invention further contemplates a method of assembling a vapor separator, substantially in accordance with the above summary.
In a particularly preferred form of the invention, the aspects of the invention summarized above are together incorporated into a vapor separator, thus substantially reducing the number of hose connections and greatly facilitating assembly of the various components to the engine.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.